Image processing apparatus utilizing the JBIG method, having a compression/expansion circuit to manage memory more effectively

Abstract

An image processing apparatus stores image data by compressing the image data in succession to a predetermined resolution, comparing the data before compression and the data after compression at each stage of the compressions to generate encoded data, and storing thus compressed image data and a plurality of thus generated encoded data in a memory. For image display or image output, the image data of a resolution required for such image display are prepared from the compressed image data and the encoded data stored in the memory. Thus conversion of image data from the original resolution to the resolution required in the display can be dispensed with.

What is claimed is: 
     
       1. An image processing apparatus comprising: input means for entering image data;   first data memory means for storing said image data;   compression means for compressing said image data a predetermined number of times to prepare data of a predetermined resolution;   generation means for comparing data before each said compression time with data after each said compression time after each said compression by said compression means, thereby generating encoded data;   second data memory means for storing the data of said predetermined resolution and a plurality of said encoded data; and   output control means for preparing data of a desired resolution from the data of predetermined resolution and the encoded data stored in said second data memory means, and supplying said prepared data to output means.   
     
     
       2. An image processing apparatus according to claim 1, wherein said second data memory means includes plural areas for storing data of said predetermined resolution, and plural image data entered from said input means are respectively compressed to the data of predetermined resolution by said compression means, and are respectively stored in the plural areas of said second data memory means. 
     
     
       3. An image processing apparatus according to claim 1, wherein said output means includes a display device. 
     
     
       4. An image processing apparatus according to claim 1, further comprising expansion means for expanding the data of said predetermined resolution, wherein said output means is adapted to effect the output of the data expanded by said expansion means. 
     
     
       5. An image processing apparatus according to claim 1, further comprising division means for dividing the data, stored in the first data memory means, into plural parts, wherein said compression means is adapted to compress a predetermined number of times the data divided by said division means. 
     
     
       6. An image processing apparatus comprising: first data memory means for storing image data;   compression means for compressing said image data a predetermined number of times to prepare data of a predetermined resolution;   generation means for comparing data before each said compression time with data after each said compression time after each said compression by said compression means, thereby generating encoded data;   second data memory means for storing the data of said predetermined resolution and a plurality of said encoded data;   comparator means for comparing the size of an empty area of said second data memory means with the size of data of said predetermined resolution;   re-compression means for compressing the data of said predetermined resolution, in case said comparator means identifies that the size of the empty area of said second data memory means is smaller than the size of data of said predetermined resolution; and   memory control means for storing the data, compressed by said re-compression means, in said second data memory means.   
     
     
       7. An image processing apparatus according to claim 6, wherein said second data memory means includes plural areas for storing the data of said predetermined resolution, and said comparator means is adapted to effect comparison with each of said plural areas. 
     
     
       8. An image processing apparatus comprising: original data memory means for storing data;   compression means for compressing the data;   comparator means for comparing said data with the data compressed by said compression means;   encoded data generation means for generating encoded data, based on the result of comparison by said comparator means;   control means for activating said compression means, comparator means and encoded data generation means by a predetermined number of times in repetition;   memory means for storing, in succession, said encoded data generated under the control by said control means;   data memory means for storing data generated by the activations of said predetermined number of times of said compression means, under the control by said control means;   first display control means for displaying the data, stored in said data memory means, in a first area of display means;   instruction means for instructing the display of the data displayed in said first area, into a second display area of the display means;   expansion means for expanding the data, stored in said data memory means, according to the encoded data stored in said memory means, under the instruction by said instruction means; and   second display control means for displaying the data, expanded by said expansion means, in said second display area.   
     
     
       9. An image processing method comprising steps of: entering image data;   compressing the entered image data a predetermined number of times to form compressed image data;   comparing image data before compression with image data after compression;   generating encoded data based on the result of said comparison;   storing said compressed image data and the encoded data in memory means; and   supplying said compressed image data to output means.   
     
     
       10. An image processing method comprising the steps of: storing image data in memory means;   compressing said image data a predetermined number of times to prepare data of a predetermined resolution;   comparing data before compression with data after compression at each time of said compression, thereby generating encoded data;   storing the data of said predetermined resolution and a plurality of said encoded data in memory means;   comparing the size of the empty area of said memory means with that of the data of said predetermined resolution; and   storing the data of said predetermined resolution and a plurality of said encoded data in the data memory means if the size of the empty area of said memory means is larger than that of the data of said predetermined resolution; but   re-compressing the data of said predetermined resolution if the size of the empty area of said memory means is smaller than that of the data of said predetermined resolution; and   storing said re-compressed data in said memory means.   
     
     
       11. An image processing method comprising the steps of: storing data in original memory means;   compressing said data;   comparing said data with the data compressed by compression means;   generating encoded data based on the result of said comparison;   repeating said compression, comparison and generation of encoded data by a predetermined number of times;   storing said encoded data, generated by said repetition by a predetermined number of times, in succession in memory means;   storing compressed data, generated by said repetition by a predetermined number of times, in data memory means;   displaying the data, stored in said data memory means, in a first area of display means;   instructing the display of data displayed in said first display area into a second display area of the display means;   expanding, in response to said instruction, the data stored in said data memory means according to the encoded data stored in said memory means; and   displaying said expanded data in said second display area.